tbuckley/cabot-search huggingface dataset:
Abstract P2019: Diastolic Dysfunction In Alzheimer's Disease Is Associated With aβ- Amyloid Aggregate Formation And Mitochondrial Dysfunction
Authors: Richa Aishwarya, Chowdhury S. Abdullah, Naznin Sultana Remex, Sadia Nitu, Karen Stokes, Md Shenuarin Bhuiyan
Journal: Circulation Research (2023)

Background: Alzheimer's disease (AD) is a neurodegenerative disease with memory impairment caused by an accumulation of toxic protein aggregates (Aβ- amyloid plaques and tau-derived neurofibrillary tangles). Several studies reported cardiovascular abnormalities with diastolic dysfunction in AD patients; however, the direct mechanism of cardiac dysfunction in AD patients remains unexplored. Therefore, we investigated the pathophysiological mechanism of cardiac dysfunction in the mice model of AD. Hypothesis: Two most commonly used mice models of AD was thoroughly evaluated for cardiac dysfunction, histopathology, and biochemical changes over aging. Methods and Result: To determine the mechanism of AD-associated cardiac dysfunction, we used two different AD mice models: double transgenic mice expressing a chimeric mouse/human amyloid precursor protein and a mutant human presenilin 1 (APP/PS1 Tg), and transgenic mice that is homozygous for a Psen1 mutation and the co-injected APPSwe and tauP301L transgenes (3xTg-AD). Cardiac function measurement using non-invasive echocardiography in aged Ntg and AD mice models showed no difference in systolic cardiac functional parameters. However, diastolic function assessment using Doppler echocardiographic measurements showed ventricular diastolic dysfunction with reduced diastolic filling in APP/PS1 Tg and 3xTg-AD mice. Western blot analysis showed Aβ- amyloid protein expression in APP/PS1 Tg hearts. Immunohistochemical and immunofluorescence staining of the APP/PS1 Tg heart sections further confirmed the Aβ- amyloid protein expression and Aβ- amyloid aggregate formation in the cardiomyocytes. Further evaluation of APP/PS1 Tg hearts demonstrated increased collagen deposition (Picro-Sirius red staining) and increased cardiomyocyte cross-sectional area. Interestingly, APP/PS1 Tg hearts also displayed mitochondrial dysfunction with decreased mitochondrial bioenergetics and significantly reduced mitochondrial function regulatory parameters. Conclusion: Overall, we found diastolic dysfunction development with Aβ- amyloid aggregate formation, fibrotic remodeling, increased cardiomyocyte cross-sectional area, and mitochondrial dysfunction in the AD mice hearts.
Abstract P3133: Role Of Myofilament-associatedNeuronal NOSFor Ca <sup>2+</sup> Desensitization Via Troponin I Phosphorylation In The Right Ventricular Cardiomyocytes Of Rats
Authors: Young Keul Jeon, Jae Won Kwon, Sung Joon Kim
Journal: Circulation Research (2023)

This study aimed to compare the role of neuronal nitric oxide synthase (nNOS, NOS1) in the excitation-contraction coupling and myofilament Ca 2+ -sensitivity between left ventricular cardiomyocytes (LVCMs) and right ventricular cardiomyocytes (RVCMs). Previous research had only investigated the effects of nNOS on LVCMs, but our study focused on RVCMs which have slightly larger diastolic sarcomere length (SL D ) and smaller sarcomere shortening (ΔSL) than LVCMs. Immunoblot study showed that the total expression and phosphorylated Ser 1417 ratio of nNOS were not different between RVCMs and LVCMs. However, treating RVCMs with the nNOS-specific inhibitor, S-methyl-L-thiocitrulline (SMTC), resulted in more prominent augmentation of ΔSL and shortened SL D in RVCMs, along with a paradoxical decrease of the amplitude of Ca 2+ transient (Δ[Ca 2+ ] i ) due to a more significant inhibition of L-type Ca 2+ current in RVCMs. The Ca 2+ -contraction loop showed a more leftward shift in the RVCMs by nNOS inhibition, indicating Ca 2+ desensitization of the myofilaments by the intrinsic nNOS. Previous studies offered troponin I (cTnI) phosphorylation as the regulatory target of myofilament Ca 2+ -sensitivity through the sGC-cGMP-PKG pathway downstream to NO. The SMTC treatment decreased cTnI phosphorylation in the RVCMs, while not in the LVCMs, suggesting that nNOS plays a more prominent role in myofilament Ca 2+ desensitization in RVCMs by targeting cTnI. Additionally, the higher phosphorylation of nNOSβ, the isoform of nNOS expressed in the myofilaments, was detected in the myofilament of RVCMs than LVCMs. This study is the first to demonstrate the more significant role of nNOS in RVCMs in regulating myofilament Ca 2+ desensitization through cTnI.
Abstract P2160: High-throughput Imaging Of Cardiomyocytes Using Biomimetic Tools Help Identify Therapeutic Targets
Authors: Hannah M Kleppe, Rishikesan Chandrakumar, Rebecca E Slater, Sylwia M Figarska, Anastasiia Budan, Alan R Levinson, James R Priest, Tim Hoey
Journal: Circulation Research (2023)

Cardiovascular disease is a leading cause of death and continues to require novel forms of therapies. Mutations in sarcomeres, the basic contractile units of cardiac muscle, causing disarray and loss of function are causal in many genetic cardiomyopathies. Here, we model sarcomeric disarray in vitro by culturing human induced pluripotent stem cell-derived cardiomyocytes (human iPSC-CMs) on tissue culture plates with biomimetic patterned grooves designed to simulate extracellular matrix. This culture system models the natural structure and phenotypic development of human physiology. Next, we created an Adeno-associated virus open reading frame (AAV-ORF) library of ~100 heart failure associated genes of interest (GOI) identified using publicly available human genetic data. We developed a high throughput screening (HTS) process to test the effects of overexpression of these GOIs on sarcomere morphology. Images of human iPSC-CMs treated with overexpression libraries were run through a custom MATLAB HTS image processing script named ‘Tamarack’, developed for quantifying human iPSC-CM sarcomere morphology. Tamarack enables quantification of sarcomere count, length, and orientation. Analysis of sarcomeres from the Tamarack code in the biomimetic plates allows for enhanced quantification of sarcomere structures, in particular, alignment, a metric missing from standard 2D culture plates. We found that treating cells with siRBM20 induced a sarcomere misalignment phenotype which we looked to rescue with overexpression of our GOI. Genes that increased alignment in an RBM20 background were considered top hits and moved to further analysis.
Abstract P3136: Alternative Polyadenylation Of Scn5a Generates A Novel N-terminal Nav1.5 Microprotein
Authors: Nathan H Witmer, Jared M McLendon, Xiaoming Zhang, Colleen Stein, Jin-Young Yoon, Barry London, Ryan L Boudreau
Journal: Circulation Research (2023)

SCN5A encodes the cardiac voltage-gated Na+ channel, NaV1.5, that initiates the cardiac action potential. Its expression and activity are highly regulated, and variants can cause arrhythmias and increased heart failure risk. Mechanisms controlling NaV1.5 expression and activity are not fully understood. We recently discovered a well-conserved alternative polyadenylation (APA) signal downstream of the first coding exon in SCN5A. The APA signal yields a short SCN5A transcript, resulting in the presence of mRNA-seq reads mapping to this intronic region in heart tissues from several species (e.g. human, pig, and cat; rodents lack the upstream APA). Analysis of cardiac APA data revealed a decrease in upstream APA signal usage in humans with dilated cardiomyopathy (~30%, p=0.08). Reanalysis of human cardiac RNA-seq data indicated the ratio of short/full-length SCN5A mRNA is reduced ~25% in failing hearts (p&lt;0.05, versus non-failing hearts). Notably, the short transcript isoform has the potential to produce a novel microprotein (referred to as SCN5A-NT), which is composed of an N-terminus identical to NaV1.5 and a unique C-terminus derived from “intronic” sequence. Western blot of human heart tissue using an N-terminal NaV1.5 antibody shows a band migrating identically to transgene-derived SCN5A-NT, supporting its expression in human hearts. SCN5A-NT is predicted to contain a mitochondrial targeting sequence, and immunostaining of transgene-derived SCN5A-NT in neonatal rat cardiomyocytes colocalizes with mitochondria. These findings were corroborated in mice treated with AAV9 encoding SCN5A-NT, which showed myocardial SCN5A-NT expression by western blot and immunostaining that colocalized to cardiomyocyte mitochondria. We are currently devising cell culture and mouse experiments to test if SCN5A-NT alters mitochondrial functions and/or NaV1.5 activity, perhaps by modulating mitochondria ROS or NAD+/NADH. We also generated knock-in mice harboring the human APA signal to investigate how upstream APA influences NaV1.5 expression and whether upstream APA usage is dynamically regulated during cardiac stress. Overall, this work describes a new regulatory mechanism of NaV1.5 expression that yields an undescribed microprotein.
Abstract P1168: Hippo Signaling Interacts With Tgfb Pathway To Regulate Pacemaker Cell State And Fibrosis In The Sinoatrial Node
Authors: Mingjie Zheng, Xiao Li, Jun Wang
Journal: Circulation Research (2023)

Rhythmic heartbeats are initiated by electrical impulses from pacemaker cells (PCs) within the sinoatrial node (SAN). Fibroblasts provide structure support for PCs in the SAN, yet excessive fibrosis causes cardiac diseases and arrhythmias. Here we found that Hippo signaling cell-autonomously controls the cell state of PCs and non-cell-autonomously regulates the proliferation of fibroblasts in the SAN. Conditional knockout of Hippo signaling kinases Lats1 and Lats2 in PCs of adult mice ( Lats1/2 CKO) leads to SAN fibrosis and cardiac arrhythmias. RNAscope and immunostaining data indicated significantly increased Tgfβ1 and pSmad3 (Tgfβ signaling effector) in the SANs of Lats1/2 CKO compared to controls. Treatment with Tgfβ receptor inhibitor significantly reduced fibroblasts proliferation in Lats1/2 CKO, suggesting that Lats1/2 deletion caused fibrosis is partially mediated through Tgfβ signaling. Single-cell (sc)-multi-omics data (paired scRNA-seq and scATAC-seq) from control and Lats1/2 CKO SANs indicated that among three subtypes of PCs (PC1-PC3, classification based on their transcriptomic profile and chromatin accessibility), PC3 had the most upregulation of Yap (Hippo signaling effector) target genes in response to Lats1/2 deletion. Notably, Lats1/2 CKO PC3 was featured by highly increased expression of the smooth muscle genes, suggesting a smooth-muscle-like cell state change in PC3 after Lats1/2 deletion. Moreover, compared to controls, smooth-muscle-like PCs of Lats1/2 CKO had increased expression of Tgfβ ligands and Smad2/3, as well as Yap/Smad co-activation of smooth-muscle genes. In response to these changes in the smooth-muscle-like PCs of Lats1/2 CKO, fibroblasts exhibited increased expression of Tgfβ receptors. These PCs state changes and PC-fibroblasts communications likely lead to increased fibrosis and arrhythmias in Lats1/2 CKO. Taken together, our findings suggest that the Hippo signaling crosstalk with Tgfβ pathway regulates PC state and PC-fibroblasts communication.
Abstract P2139: The Adiponectin Receptor Agonist ALY688 Prevents Pressure Overload-induced Cardiac Dysfunction And Adverse Cardiac Remodeling
Authors: Sungji Cho, Keith Dadson, Kathryn Crawford, Henry Hsu, Gary Sweeney
Journal: Circulation Research (2023)

Adiponectin has been shown to mediate multiple cardioprotective effects. Since the use of adiponectin protein as a practical therapeutic is associated with multiple challenges, we examined the functional significance of targeting adiponectin signaling with ALY688, a small peptide-based adiponectin mimetic, in a mouse model of cardiac dysfunction caused by left ventricular pressure overload (PO) induced by minimally invasive transverse aortic banding (MTAB). Following daily administration of ALY688 over 5 weeks after induction of PO, echocardiography showed that significantly attenuated PO-induced reduction in ejection fraction and other indices of cardiac function compared with vehicle. ALY688 also significantly reduced cardiac hypertrophic remodeling (heart weight-to-tibia length), cardiomyocyte cross sectional area, and myocardial and circulating levels of serum natriuretic peptide A. ALY688 reduced PO-induced increases in myofibroblasts, and scar tissue collagen content based upon immunofluorescence staining for α-smooth muscle actin and vimentin, scanning electron microscopy, and picrosirius red staining. ALY688 reduced PO-induced myocardial expression of 14 pro-inflammatory genes and circulating IL-12, IL-15, IL-17, and MIP-3α levels. Targeted metabolomics revealed that ALY688 increased myocardial fatty acid oxidation, with increased mobilization of cardiac triacylglycerols and a decrease in sphingomyelin, fatty acids and lysophospholipids. In conclusion, the adiponectin analogue ALY688 is cardioprotective in a preclinical animal model of heart failure and cardiac remodeling, with beneficial metabolic, anti-fibrotic, anti-hypertrophic and anti-inflammatory properties leading to improved cardiac function.
Abstract P3014: Human Pluripotent Stem Cell-derived Organoids Yield Microvascular-like Endothelial Cells
Authors: Qasim A Majid, Virpi Talman, Sian Harding, Gabor Foldes
Journal: Circulation Research (2023)

Introduction: Coronary microvascular disease (CMD) can manifest as microvascular angina or HFpEF and is implicated in post-STEMI remodelling and COVID-19. Superior in vitro models would aid the development of therapies for CMD. This study outlines the creation of a 3D differentiation protocol that yields stable human pluripotent stem cell-derived microvascular-like endothelial cells (hPSC-MVECs). Hypothesis: We hypothesised that the 3D organoid environment would allow for recapitulation of the microvasculature. Methods: Growth factor-mediated endothelial differentiation of hPSCs was conducted for 12 days in stirred tank bioreactors devoid of exogenous matrix substrates such as Matrigel. CD31 pos 3D-derived hPSC-ECs were isolated via fluorescence-activated cell sorting and evaluated via RT-qPCR for their gene expression of endothelial markers relative to 2D-derived hPSC-ECs. 3D hPSC-ECs were subsequently treated with high concentration VEGFA for 7 days (3D+V) and assessed for CD31 expression via high content image analysis. A proteome profiler human angiogenesis array was employed to investigate the angiogenic landscape of the generated hPSC-ECs relative to primary Human Cardiac Microvascular Endothelial Cells (HMVEC-Cs). Transcriptomic analysis of the ECs was conducted via Single-Cell RNA sequencing (scRNA-seq). Results: Organoids attained on day 12 of the 3D differentiation protocol displayed a complex vascular network. Isolated 3D hPSC-ECs displayed comparable levels of PECAM1 and CDH5 relative to 2D hPSC-ECs however, the expression of VEGFA was significantly reduced (P&lt;0.01). The resultant high-concentration treatment with exogenous VEGFA gave rise to phenotypically stable hPSC-ECs that had an angiogenic profile comparable to HMVEC-Cs. scRNA-seq for 3D+V hPSC-ECs revealed expression of several reported microvascular markers including GJA4 (arteriole), S100A4 (post-arteriole capillary), TCF15 (capillary), SOX17 (pre-venular capillary), CD34 (venule), and the coronary vessel marker FABP4 . Conclusions: These data suggest that 3D organoid differentiation facilitates the generation of cardiac microvascular-like ECs herein termed hPSC-MVECs.
Abstract P1179: Evaluation Of A Machine Learning-based Metabolic Marker For Coronary Artery Disease In The UK Biobank
Authors: Kyle M Gibson, Iain Forrest, Ben O Petrazzini, Aine Duffy, Joshua K Park, Ghislain Rocheleau, Daniel Jordan, Ron Do
Journal: Circulation Research (2023)

A recent study has shown that an in silico quantitative score of CAD (ISCAD) can be built using machine learning and clinical data from electronic health records. ISCAD was shown to be associated with CAD risk, atherosclerosis, sequela and all-cause mortality. We developed a CAD-predictive learning model using only metabolic data from 93,642 individuals from the UK Biobank (median [IQR] age, 57 [14] years; 39,796 [42%] male; 5640 [6%] with diagnosed CAD), and assessed its probabilities as a quantitative metabolic risk score for CAD (M-CAD; range 0 [lowest probability] to 1 [highest probability]) in participants of the UK Biobank. The relationship of M-CAD with arterial stiffness index, ejection fraction, CAD sequelae, and key mortality measures was assessed. The model predicted CAD with an area under the receiver-operating-characteristic curve of 0.712 in the testing set. Arterial Stiffness Index increased by 0.19 and 0.27 meters/second and ejection fraction decreased by 0.2% and 1% per 0.1 increase in M-CAD in all subjects and CAD cases, respectively. Both incident and recurrent myocardial infarction increased stepwise over M-CAD quartiles when evaluated in all participants (odds ratio (OR) 15.3 [4.2%] and 12.5 [0.2%]) and participants with CAD (OR 1.78 [34%] and 2.32 [1.7%] in top quartiles as compared to the first quartile of incident and recurrent MI respectively). Likewise, the hazard ratio and prevalence of all-cause mortality, CVD-associated mortality, and CAD-associated mortality increased stepwise over M-CAD deciles when assessed in all participants (2.98 [14%], 9.34 [4.3%], 26.7 [2.7%] in the top deciles as compared to the first decile of all-cause, CVD, and CAD mortality respectively) and a subset of participants with CAD (2.32 [24%], 2.78 [14%]], 3.41 [10%] in the top deciles as compared to the first decile of all-cause, CVD, and CAD mortality respectively. Interpretation of the model with SHAP values demonstrated that features known to be CAD risk factors contributed to the model predictions in the direction expected with their documented biological effects. We demonstrate that metabolic-based machine learning can be used to build a quantitative risk score for CAD that is associated with subclinical atherosclerosis, CAD sequala and mortality.
Abstract P2148: Beyond Traditional Pharmacology: A Critical Appraisal Of Enhanced External Counterpulsation (EECP) As A Promising Alternative Treatment For Hypertension
Authors: Abhay A Kapoor, HariOm S Vaja, Gurleen Kaur, Vraj J Rangrej, Juhu Kiran Krushna Karri, Asiff Nathi Aneef
Journal: Circulation Research (2023)

Introduction: Hypertension is a significant global public health concern and a leading cause of cardiovascular disease. Despite the availability of numerous pharmacological therapies, many hypertensive patients experience inadequate blood pressure control, medication side effects, or resistance. Thus, non-pharmacological interventions such as Enhanced External Counter pulsation (EECP) have garnered interest as a promising alternative treatment for hypertension.This systematic review aims to evaluate the existing clinical evidence on the efficacy, safety, and underlying mechanisms of EECP as a non-invasive therapy for hypertension. Eligible studies included randomized controlled trials, non-randomized controlled trials, and observational studies. Material and Methods: A comprehensive search of the MEDLINE database was done from March 2002 to March 2023 to identify studies evaluating the use of “EECP in hypertensive patients”. Initially, 31 articles were screened for eligibility, and subsequently, 9 articles met the inclusion criteria, &amp; were thereby included in the review. The inclusion criteria being relevance to the research question, thereby excluding the rest. Results: The review finds that EECP therapy can have beneficial effects on blood pressure control, endothelial function, arterial stiffness, and inflammation in patients with hypertension. The underlying mechanisms of EECP involve enhancing arterial blood flow, improving endothelial function, and reducing peripheral vascular resistance. Although the evidence base for EECP is limited, the available studies suggest that this therapy is safe and well-tolerated, with few adverse effects reported. Conclusions: EECP represents a promising alternative treatment option for hypertension beyond traditional pharmacotherapy. However, further high-quality studies are needed to confirm its efficacy and to identify optimal treatment protocols for different patient populations. Nevertheless, the current evidence suggests that EECP is a valuable addition to the armamentarium of hypertension management strategies.
Abstract P3104: Sex Differences In Vasodilation In Embryonic Coronary Arteries
Authors: Shion Nagasawa, Masami Kodama, Kazuho Sakamoto, Fujimi Kudo, Ichiro Manabe, Junko Kurokawa
Journal: Circulation Research (2023)

Sex differences exist in circulatory system and the onset of cardiovascular diseases. These differences have been thought to be due to the vasoprotective effects of estrogen. However, there are also sex differences at the early stages of life, such as the survival rate of extremely preterm infants. The mechanisms in which those sex differences are formed at first remain to be elucidated. Therefore, we analyzed the mechanism of sex differences using fetal mouse hearts. In this study, embryonic day 17.5 mice were used to understand sex differences in cardiovascular system just before they are born. First, for morpho-functional analysis of coronary arteries, hearts were removed from embryonic day 17.5 mice, and angiography was performed using nano-particle ink. The ink was injected from the aorta at a constant pressure to visualize the morphology of coronary arteries. We found a significant sex difference in coronary artery diameters. Male coronary arteries were larger under physiological conditions, on the other hand, female coronary arteries were more dilated in the presence of the NO-donor NOC7 and the ROCK inhibitor Y27632. In addition, the same tendency was observed in sections of mouse hearts at embryonic day 17.5. These findings suggest that female’s coronary arteries are more contractile than males. Next, embryonic day 17.5 mouse hearts were dissociated, then sorted with FACS to obtain endothelial cells for bulk RNA-seq and single-cell RNA-seq. Cells were clustered based on the expression of 8 sex-differential genes to identify the sex of each cell. In line with the result of coronary visualization, Gene Set Enrichment Analysis showed the gene set of smooth muscle cell contraction was upregulated in males. Furthermore, cell-cell communication analysis showed that male endothelin signals were modestly stronger in endothelial cells and smooth muscle cells. These data support our previous observation that male left coronary arteries have a larger diameter but are less reactive to vasodilators, because they may have greater contractile function. In conclusion, this study suggests that functional and morphological sex differences already exist at embryonic day 17.5.
Abstract P1078: Cardiomyocyte-fibroblast Interaction Regulates Ferroptosis And Fibrosis After Myocardial Injury
Authors: Shuang Li, Mary Mohr, Ge Tao
Journal: Circulation Research (2023)

Neonatal mouse hearts have transient renewal capacity which is lost in juvenile and adult hearts. After myocardial infarction (MI) in neonatal hearts, an initial loss of cardiomyocytes occurs but it is unclear through which type of regulated cell death (RCD). In the current studies, we induced MI in neonatal and juvenile mouse hearts, and show that ischemic cardiomyocytes primarily undergo ferroptosis, a non-apoptotic and iron-dependent form of RCD. We demonstrate that cardiac fibroblasts (CFs) protect cardiomyocytes from ferroptosis through paracrine factors and direct cell-cell interaction. CFs show strong resistance to ferroptosis due to high ferritin expression. Meanwhile, the fibrogenic role of CFs, typically considered detrimental to heart function, is negatively regulated by paired-like homeodomain 2 (Pitx2) signaling from cardiomyocytes. In addition, Pitx2 prevents ferroptosis in cardiomyocytes by regulating ferroptotic genes. Understanding the regulatory mechanisms of cardiomyocyte survival and death can identify potentially translatable therapeutic strategies for MI.